Mac doesn't accept Apple ID but on Iphone it does

Did you follow all the steps mentioned in this article, after you have changed the password?

What to do after you change your Apple ID or password - Apple Support

Are you running any anti - virus programs? Using a VPN?

Try setting up another admin user account in System Preferences/Users & Groups to see if the same problem continues. Also try the Safe Mode. 

Isolating an issue by using another user account   

Safe Mode - About.       

If it works in the Safe Mode, try running this program when booted normally and then copy and paste the output in a reply. The program was created by Etresoft, a frequent contributor.  Please use copy and paste as screen shots can be hard to read. Click “Share Report” button in the toolbar, select “Copy to Clipboard” and then paste into a reply. This will show what is running on your computer. No personal information is shown. If the log won’t post, try posting it in Pastebin and provide a link in a reply. After pasting the report in a PasteBin page, go to the top of the page, and copy the address in the URL bar. Paste that in a new reply.        Pastebin.    

Etrecheck – System Information.      

Web site version if required.  https://etrecheck.com

Sorry, but using bold fonts can make your text difficult to read for other users, and should be avoided.

Community etiquette guidelines - Apple Support

Ingo2711 Said:

"Sorry, but using bold fonts can make your text difficult to read for other users, and should be avoided.[...]"

-------

For Note: Been Using it for 15 months - ADC says they prefer it.

...

• We suggest that you avoid using all capital letters, bold fonts, or emphasized words, which may convey a negative tone.

...

copied from: Community etiquette guidelines - Apple Support

big_kahuna150 Said:

"Mac doesn't accept Apple ID but on Iphone it does"

-------

Is this a Used Mac?

If Yes:

If this is a used Mac, you need to contact the previous owner, and have them sign themselves out. Elsewise, it is a paperweight just sitting atop your desk.

If Not:

• Try Creating: a new administrator and login through it
• Try Safe Mode: Hold Down: the shift key upon boot and log in. In Safe Mode, caches(Application Setting Files) are set aside, and login items do not load upon boot.

Are you connected to wifi?